Global, regional, and national incidence and mortality burden of non-COVID-19 lower respiratory infections and aetiologies, 1990-2021: a systematic analysis from the Global Burden of Disease Study 2021

Respiratory syncytial virus vaccination in older adults and patients with chronic disorders: A position paper from the Portuguese Society of Pulmonology, the Portuguese Association of General and Family Medicine, the Portuguese Society of Cardiology, the Portuguese Society of Infectious Diseases and Clinical Microbiology, the Portuguese Society of Endocrinology, Diabetes and Metabolism, and the Portuguese Society of Internal Medicine

BACKGROUND

Respiratory syncytial virus (RSV) is an important cause of lower respiratory tract infection, hospitalisation and death in adults.

METHODS

Based on evidence regarding the impact of RSV on adult populations at risk for severe infection and the efficacy and safety of RSV vaccines, the Portuguese Society of Pulmonology, the Portuguese Association of General and Family Medicine, the Portuguese Society of Cardiology, the Portuguese Society of Infectious Diseases and Clinical Microbiology, the Portuguese Society of Endocrinology, Diabetes and Metabolism, and the Portuguese Society of Internal Medicine endorses this position paper with recommendations to prevent RSV-associated disease and its complications in adults through vaccination.

CONCLUSION

The RSV vaccine is recommended for people aged ≥50 years with risk factors (chronic obstructive pulmonary disease, asthma, heart failure, coronary artery disease, diabetes, chronic kidney disease, chronic liver disease, immunocompromise, frailty, dementia, and residence in a nursing home) and all persons aged ≥60 years. If it cannot be made available to this population, then the vaccine should be prioritised for individuals aged ≥75 years and those aged ≥50 years with risk factors. The vaccine should preferably be given between September and November and can be co-administered with the influenza vaccine. Ongoing studies on RSV vaccines may justify extending these recommendations in the future.

Viral respiratory tract infections diagnosis: a Spanish survey and consensus approach

BACKGROUND

Respiratory tract infections (RTI) rank second cause of adult and paediatric morbidity and mortality worldwide. Clinical symptoms of acute respiratory infections (ARIs) do not allow to differentiate one from another. The etiological diagnosis of viral respiratory infections has undergone changes throughout the 21st century pandemics. In Spain there is still no consensus on the use of molecular tools for the diagnosis of viral RTI.

METHODS

A panel of specialists from various Spanish Scientific Societies was gathered to discuss about the application of diagnostic techniques for respiratory viruses. A Delphi panel was conducted throughout 3 rounds, respondents being asked to rate their agreement level to provide evidence-based consensus methods to enable rapid and accurate diagnosis of viral RTI.

RESULTS

The Delphi panel of experts reached a strong consensus that viral infections are the main cause of ARI, with Influenza, RSV, and SARS-CoV-2 identified as the most significant pathogens. These viruses are also the leading cause of ARI-related complications in vulnerable patients with risk factors for severe disease. In hospital settings, all symptomatic ARI patients should undergo rapid PCR testing for these three viruses, a measure of critical importance for immunocompromised individuals, the very elderly, and those with comorbidities that may worsen clinical outcomes.

CONCLUSION

Experts main concern was directed towards the need to inform and familiarize non-specialists about the relevance of specific viral diagnosis result of this diagnostic approach would be the reduction of antibiotic use for hospital and primary health providers.

6-plex Crystal Digital PCR® for comprehensive surveillance of respiratory and foodborne bacterial pathogens in wastewater

Bacterial wastewater surveillance (WS) is less explored area compared to viral WS despite high burden of bacterial respiratory and gastrointestinal infections worldwide. This study established a 6-plex Crystal Digital PCR® (cdPCR) system, to comprehensively monitor an acute respiratory pathogen - Group A Streptococcus (GAS) pyogenes, foodborne disease (FBD) pathogens - Clostridium perfringens, Salmonella spp., Campylobacter jejuni, and Campylobacter coli, and an indicator bacterium, Escherichia coli in wastewater. Fifty-two grab influent samples collected weekly from a wastewater treatment plant in Yamanashi Prefecture, Japan, between June 2023 and May 2024 were centrifuged, followed by DNA extraction and cdPCR. cdPCR was performed using the naica® system (Stilla Technologies). The 6-plex cdPCR assays showed strong performance. Among the 52 samples, 100 % of samples were positive for C. perfringens, 98 % for Salmonella spp., 56 % for C. jejuni, 25 % for C. coli, and 63 % for S. pyogenes, with concentrations ranging between 4.2 ± 0.3 to 7.5 ± 0.2 log10 copies/L. The concentration of C. perfringens was significantly higher than that of other pathogens (p < 0.05), indicating its dominance. Salmonella spp. had high detection rate, implying increased Salmonella infection in the population. Seasonal variation was not observed in any of FBD pathogens, except for the detection rate of C. coli. S. pyogenes concentrations were significantly higher in spring than in other seasons, agreeing with the trend of GAS pharyngitis cases in the catchment. In conclusion, the 6-plex cdPCR system is a valuable tool for comprehensive WS, offering significant implications for public health monitoring.

Perceptions of hospital feeding practices among mothers of infants with severe pneumonia in Malawi: a qualitative descriptive study

OBJECTIVE

To determine caregiver knowledge of, attitudes towards, and perceptions of feeding practices for infants admitted to a tertiary referral hospital with severe pneumonia, and to identify community feelings about nasogastric tube feeding in Malawi.

SETTING

The paediatric ward of a government tertiary referral hospital in Lilongwe, Malawi.

METHODS

From March through April 2023, we conducted in-depth interviews with 14 mothers of infants 0-12 months of age hospitalised with severe pneumonia who had been enrolled in an observational study evaluating feeding and swallowing in breastfed infants. In-depth interviews assessed mothers' attitudes towards hospital feeding practices including nasogastric tube feeding, along with community perceptions of nasogastric tubes. Data were analysed using a thematic analysis approach to assess themes and subthemes of transcripts.

RESULTS

Mothers understood that children with pneumonia are at risk of 'choking' during oral feeding; however, they had substantial worries about both withholding breastfeeding and providing nasogastric feeds to their infants through a nasogastric tube. Community perceptions of nasogastric tubes were widely negative and included beliefs that nasogastric tubes cause children to 'choke' and die and that medical providers want to harm children. Mothers held strong beliefs about the benefits of breastfeeding.

CONCLUSION

There are alarming misconceptions in the community around nasogastric tubes and the intentions of medical providers. This leads to maternal concerns about this hospital feeding practice, poor adherence to medical recommendations, and mistrust in the broader healthcare system. To improve hospital outcomes of children with severe pneumonia, caregiver and community education is needed.

Role of the upper airway microbiota in respiratory virus and bacterial pathobiont dynamics in the first year of life

The mechanisms by which respiratory viruses predispose to secondary bacterial infections remain poorly characterized. Using 2,409 nasopharyngeal swabs from 300 infants enrolled in a prospective cohort study in Botswana, we perform a detailed analysis of factors that influence the dynamics of bacterial pathobiont colonization during infancy. We quantify the extent to which viruses increase the acquisition of Haemophilus influenzae, Moraxella catarrhalis, and Streptococcus pneumoniae. We provide evidence of cooperative interactions between these pathobionts while identifying host characteristics and environmental exposures that influence the odds of pathobiont colonization during early life. Using 16S rRNA gene sequencing, we demonstrate that respiratory viruses result in losses of putatively beneficial Corynebacterium and Streptococcus species that are associated with a lower odds of pathobiont acquisition. These findings provide important insights into viral-bacterial relationships in the upper respiratory tract of direct relevance to respiratory infections and suggest that the bacterial microbiota is a potentially modifiable mechanism by which viruses promote bacterial respiratory infections.

A role for genomics-based studies of Bordetella pertussis adaptation

PURPOSE OF REVIEW

Cases of whooping cough (pertussis) have rebounded strongly from the very low incidence observed during the pandemic. This re-emergence is characterized by changes in epidemiology. Here we describe the importance of genomics to monitor and understand the drivers to these changes.

RECENT FINDINGS

Changes in the genotype of strains isolated during recent outbreaks suggests that the pandemic disturbed the global Bordetella pertussis population structure. The emergence of dominant and antibiotic-resistant clones in China is of concern even though the source of antibiotic selection pressure on B. pertussis is unclear. A recent study illustrates how to use genomic data to go beyond just surveillance, inferring the relative fitness of genotypes and the identification of specific mutations distinguishing such lineages. Such approaches are required to understand the forces driving adaptation.

SUMMARY

Pertussis is resurgent in many countries, involving changes in epidemiology and strong suggestions of strain adaptation. The continued use of vaccination, and design of new interventions, to control pertussis requires an understanding of these changes. Genomic analyses will be key to this, involving integration of more complete host and pathogen parameters than have been used to date.

Global, Regional, and National Burden of Pulmonary Fungal Infections 1990-2021

Rationale: The lungs are the most prevalent site for invasive fungal infections, and the diagnosis and treatment of pulmonary fungal infections (PFIs) pose significant challenges, accompanied by a substantial disease burden. Global factors will likely enhance the risk of PFIs in the future. Assessing the global burden of PFIs is crucial for implementing appropriate measures for prevention and control. Objectives: To evaluate the burden of PFIs at the global, regional, and national levels from 1990 to 2021 and make projections for 2044. Methods: Data on deaths and disability-adjusted life years due to PFIs were extracted from the Global Burden of Disease database. Linear regression, complex inequality measures, and the Nordpred model were used for analysis and visualization. Measurements and Main Results: In 2021, the global incidence of PFIs was estimated at 5.62 million cases (95% uncertainty interval [UI], 4.93 to 6.40 million), with 45,542 deaths (95% UI, 39,299 to 51,944). The age-standardized mortality rate was 0.56 per 100,000 (95% UI, 0.48 to 0.64 per 100,000). From 1990 to 2021, the estimated annual percentage change was -1.03% (95% confidence interval, -1.13% to -0.93%), with an observed increase in mortality rates in low- and middle-income countries. The mortality rate significantly increased among individuals aged ⩾50 years. By 2044, more than 87,000 deaths are expected from PFIs, at a rate of about 0.58 per 100,000. Conclusions: PFIs represent a significant global challenge that warrants attention and necessitates international collaboration to collectively address this issue.

Significant rise of Chlamydia pneumoniae infection in 2024 in Marseille, France

OBJECTIVES

We detected in October 2024 an abnormally high number of Chlamydia pneumoniae diagnoses through real-time surveillance of infections in Southeastern France, which followed significant increases in Mycoplasma pneumoniae and Bordetella pertussis diagnoses. Therefore, we retrospectively analyzed C. pneumoniae quantitative polymerase chain reaction (qPCR) results performed on respiratory samples collected between 2018 and 2024 in our center and described features of these infections.

METHODS

C. pneumoniae qPCR was part from a multiplex syndromic panel or an in-house simplex qPCR assay. Next-generation sequencing was performed directly on available respiratory sample residues using Oxford Nanopore/Illumina technologies.

RESULTS

We observed a 19-fold increase of C. pneumoniae qPCR positivity in 2024 vs 2018-2023. Five (0.02%) of 25,255 respiratory samples were positive during 2018-2022, five (0.12%) of 4294 in 2023, and 37 (0.64%) of 5795 in 2024 (21 during September to October). Cases were mostly in children, followed by young adults. The highest incidence was in children aged 11-15 years (eight of 1075, 0.7%) and 6-10 years (eight of 1669, 0.5%). We obtained four (near) full-length C. pneumoniae genomes. They were of serotype ST16 and those the most closely related with each other, apart from the six other ST16 genomes from GenBank, suggesting an epidemic spread in our area.

CONCLUSIONS

The present findings warrant a close monitoring of diagnoses of C. pneumoniae infections at the local and country scales and to implement genomic surveillance and characterize drug resistance for diagnosed cases.

Global trends in staphylococcus aureus-related lower respiratory infections from 1990 to 2021: findings from the 2021 global burden of disease report

BACKGROUND

Lower respiratory infections (LRIs) represent a significant global health issue, especially affecting low- and middle-income countries. In this study, we explored the mortality and disability-adjusted life years (DALYs) associated with Staphylococcus aureus-related LRIs from 1990 to 2021, highlighting trends by age, sex, and Socio-Demographic Index (SDI).

METHODS

Data were derived from the 2021 Global Burden of Disease (GBD) database. Temporal trends in age-standardized mortality rates (ASMR) and disability-adjusted life years (DALYs) rates (ASDR) for S. aureus-related LRIs were analyzed based on the average annual percent change (AAPC), in terms of sex, 20-age groups, 21 regions, 204 countries, and 5 SDI quintiles.

RESULTS

In 2021, S. aureus-related LRIs contributed to 423,837 deaths (95% UI: 382,183-458,926), a 67.56% increase since 1990. In comparison, the global ASMR was 5.43 per 100,000 (95% UI: 4.89-5.90), and the ASDR was 156.80 per 100,000 (95% UI: 139.44-176.08), both exhibiting a declining trend compared to 1990. Rates were higher in low SDI regions, with Central Sub-Saharan Africa reporting the highest ASMR, while Eastern Europe had the lowest. Among the 204 countries analyzed, Zimbabwe recorded high ASMR and ASDR, at 24.84 (95% UI: 19.44-30.16) and 754.34 (95% UI: 591.05-923.06), respectively.

CONCLUSIONS

Although the global ASMR and ASDR decreased in 2021, the number of deaths from S. aureus-related LRIs significantly increased driven by the growing population and proportion of aged individuals. Additionally, the emergence of multidrug-resistant strains has made treatment more complex, particularly in low SDI regions, highlighting the urgent need for more targeted strategies, therapies, and vaccines.

180-day efficacy of nirsevimab against hospitalisation for respiratory syncytial virus lower respiratory tract infections in infants (HARMONIE): a randomised, controlled, phase 3b trial

BACKGROUND

Respiratory syncytial virus (RSV) is a leading cause of lower respiratory tract infection and hospitalisations in infants worldwide. The primary analyses of HARMONIE showed that nirsevimab reduced infant hospitalisations due to RSV-associated lower respiratory tract infection through the RSV season. This analysis aims to evaluate nirsevimab's efficacy at 180 days after dosing, a period exceeding the typical 5-month RSV season.

METHODS

HARMONIE is an ongoing, open-label, parallel arm, randomised, controlled, phase 3b study conducted in France, Germany, and the UK. Infants aged 12 months or younger, born at a gestational age of at least 29 weeks, were randomly assigned (1:1) to receive either a single intramuscular dose of nirsevimab (50 mg for children <5 kg or 100 mg for children ≥5 kg) or standard care (without RSV prophylaxis) before or during their first RSV season. Randomisation was electronically done, stratified by country and age-group. The primary efficacy endpoint for this analysis was the incidence of hospitalisations due to RSV-associated lower respiratory tract infection up to 180 days after nirsevimab administration or randomisation in all randomised participants. Safety up to 365 days following nirsevimab administration was also assessed. This trial is ongoing and registered with ClinicalTrials.gov, number NCT05437510.

FINDINGS

Between Aug 8, 2022, and Feb 28, 2023, 8057 infants were randomly assigned to either the nirsevimab group (n=4038) or the standard care group (n=4019). The median age at randomisation was 4·00 months (IQR 1·0-7·0; range 0·0-12·0, and 4195 (52·1%) were male and 3862 (47·9%) were female. Up to 180 days, 12 (0·3%) of 4038 infants in the nirsevimab group and 68 (1·7%) of 4019 infants in the standard care group had been hospitalised for RSV-associated lower respiratory tract infection, corresponding to a nirsevimab efficacy of 82·7% (95% CI 67·8-91·5; p<0·0001). Most participants experienced grade 1 (2759 [68·7%] of 4016 in the nirsevimab group; 2696 [67·1%] of 4018 in the standard care group) or grade 2 (1447 [36·0%] of 4016 in the nirsevimab group; 1436 [35·7%] of 4018 in the standard care group) treatment-emergent adverse events, and no apparent safety concerns were raised up to 365 days after dosing.

INTERPRETATION

Nirsevimab offers consistent and sustained protection against hospitalisation due to RSV-associated lower respiratory tract infection for at least 6 months. This finding provides global health systems greater flexibility when implementing nirsevimab, providing substantial benefit in the ongoing effort to reduce the burden of infant RSV and the potential wider public health value.

FUNDING

Sanofi and AstraZeneca.

Pediatric pneumonia across altitudes in Ecuador: a countrywide, epidemiological analysis from 2010-2021

BACKGROUND

In Ecuador, pneumonia is a significant pediatric health challenge and a leading cause of infant mortality. Little is known about the contribution of altitude to trends in pneumonia incidence and mortality. The objective of this study was to examine the how the disease burden of pneumonia varies across substantial changes in altitude in a large population over time.

METHODS

A nationwide descriptive ecological analysis of the burden of pediatric pneumonia was conducted using secondary data from hospital discharges spanning 2010 to 2021. Patients aged 0 to 18 years with ICD-10 diagnoses related to pneumonia were included. The data were stratified by altitudes using the two main classifications available: The classical categorization (low < 2,500 m and high altitude > 2,500 m), and the classification offered by the International Society of Mountain Medicine (low altitude (< 1,500 m), moderate altitude (1,500 m - 2,500 m), high altitude (2,500-3,500 m). Disease frequency, prevalence, and the burden of disease were analyzed in relation to altitude.

RESULTS

Between 2010 and 2021 in Ecuador, there were 268,895 pediatric hospitalizations and 4,669 deaths due to lower respiratory tract infections. The incidence was higher among males (54.3%), who had a mean age of 1.4 years during their hospital stay. In comparison, females accounted for 45.7% of cases and had a slightly higher mean age of 1.6 years. The incidence rate in low altitude areas (< 2,500 m) was 341.6 per 100,000 with 173,305 cases, whereas high altitude areas (> 2,500 m) had a rate of 467.4 per 100,000 with 95,590 cases. The mortality rate was disproportionately high in very high-altitude regions at 34.2 per 100,000, despite lower incidence rates.

CONCLUSIONS

In Ecuador, pneumonia incidence notably increases at altitudes above 2,500 m, while mortality rates were higher at elevations exceeding 3,500 m. This increment in mortality may be attributed to reduced access to medical services in higher altitudes, leading to fewer individuals seeking early medical intervention and underreporting of incidence rates. The multifaceted nature of these findings underscores the necessity for tailored health strategies that prioritize improved healthcare accessibility, widespread vaccination programs, to mitigate the impact of pneumonia across varying altitudes.

Impact of temperature variations on burden of lower respiratory infections under climate change (1990-2021)

OBJECTIVES

We aimed to evaluate the global burden and trends of lower respiratory infections (LRIs) attributable to non-optimal temperatures between 1990 and 2021, focusing on age, period, and cohort effects as well as health inequalities to inform targeted public health policies.

METHODS

Using the Global Burden of Disease 2021 database, we obtained the age-standardized mortality rate (ASMR) and disability-adjusted life-years rate (ASDR) for LRIs related to non-optimal temperatures. We calculated estimated annual percentage changes (EAPC) to assess LRIs burden trends and applied age-period-cohort modeling to quantify age, period, and cohort effects. Health inequalities were evaluated using the slope index of inequality and the concentration index.

RESULTS

In 2021, the highest ASDR for LRIs due to high temperatures occurred in children under 5 (347.66/100,000), whereas the highest ASMR for LRIs due to low temperatures occurred in adults aged ≥ 65 (338.49/100,000). Globally, the LRIs burden from non-optimal temperatures declined (EAPC: ASMR -2.48; ASDR -3.33). However, among the five climate zones, the LRIs burden in the boreal zone due to high temperatures increased (EAPC: ASMR 24.14; ASDR 45.14), whereas all other climate zones showed decreasing trends. In lower Sociodemographic Index (SDI) regions, the high-temperature-related LRIs burden was more pronounced. Relative inequities driven by non-optimal temperatures worsened in low-SDI regions.

CONCLUSION

From 1990 to 2021, the global burden of LRIs attributable to non-optimal temperatures declined overall; however, high-temperature-related LRIs increased in boreal zones. These health inequalities underscore the urgent need for targeted climate adaptation policies, such as providing international assistance, improving infrastructure, offering healthcare resources, and promoting vaccine coverage, particularly for vulnerable populations in low-SDI regions and boreal zones.

The trends of mortality, aetiologies and risk factors of lower respiratory infections in Saudi Arabia from 1990 to 2021: results from the global burden of disease study 2021

BACKGROUND

Lower respiratory tract infections (LRIs) are the fourth leading cause of death globally, affecting all age groups and leading to over 2 million deaths annually. Saudi Arabia faces a significant burden from LRIs, affecting more than 15% of the population each year. This study aims to provide an overview of LRI mortality, etiologies, and risk factors in Saudi Arabia from 1990 to 2021.

METHOD

Data on LRI mortality in Saudi Arabia from 1990 to 2021 were extracted from the 2021 edition of the Global Burden of Disease (GBD) Result Tool. The analysis encompassed mortality rates across all age groups, with particular emphasis on children under five and adults over 70. Four primary etiologies influenza, respiratory syncytial virus (RSV), Streptococcus pneumoniae, and Haemophilus influenzae type b (Hib) were examined, alongside 14 associated risk factors.

RESULTS

The total LRI deaths in Saudi Arabia decreased by 6% from 1990 to 2021, with a significant reduction observed among children under five years old (96%). In contrast, LRI mortality among adults over 70 increased by 16% during the same period. The age-standardized mortality rate decreased by 47%, with significant reductions in deaths associated with pneumococcus and RSV. However, risk factors, such as smoking and ambient particulate matter pollution, showed minimal declines or even increased mortality rates in older adults.

CONCLUSION

Over the past three decades, Saudi Arabia has made significant progress in reducing LRI mortality, particularly among children under five. However, the increasing mortality rates among the elderly highlight the need for targeted interventions to address their unique vulnerabilities. Continued investment in public health infrastructure, vaccination coverage, and environmental health initiatives is essential for further reducing the burden of LRIs in Saudi Arabia.

Phage therapy: A novel approach to combat drug-resistant pathogens

Antibiotic-resistant infections, such as those caused by the overuse of antibiotics, have greatly strained healthcare systems. Among them, drug-resistant bacteria ESKAPE (Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, and Enterobacter species) are typical and common. Enterococcus faecalis and Escherichia coli are of equal concern. These pathogens often have higher pathogenicity than the same strains, and resistance has reduced treatment options, so new treatment options are needed to address these pathogens. This review analyzes recent studies related to phage therapy for the treatment of bacterial infections in various parts of the human body (e.g., alcoholic liver disease, skin, and soft tissues, respiratory tract, gastrointestinal tract, urinary system, etc.), to better understand the potential role of phage therapy as a non-antibiotic strategy for the treatment of infections caused by drug-resistant bacteria. In addition, this review introduces a series of products related to phage therapy and points out potential research directions for phage therapy in clinical applications. This paper elucidates the basic mechanism of human infection by some drug-resistant bacteria and the therapeutic effect of phage therapy against drug-resistant bacteria. It popularizes the understanding of phage therapy and provides a reference for research on its use for drug-resistant bacterial infections.

Epidemiological and clinical profile of viral respiratory infections in children under 5 years at pre- and post-COVID-19 era in Praia, Cabo Verde

BACKGROUND

The coronavirus disease-19 (COVID-19) pandemic has affected global health, influencing the prevalence of different respiratory pathogens. The aim of this study is to evaluate the distribution of agents causing acute respiratory infections in children under 5 years old before and after the COVID-19 pandemic in Praia, Cabo Verde, and to describe associated clinical variables.

METHODS

Conducted at the University Hospital Dr. Agostinho Neto, this study replicated methods from a previous work from 2019 (Correia et al. 2021). Nasopharyngeal samples were analysed using FilmArray® Respiratory Panel 2.1 (BioFire) to identify agents of acute respiratory infections. Molecular identification of human respiratory syncytial virus subtypes was performed using a real-time duplex reverse transcription polymerase chain reaction. Statistical analysis was performed using IBM SPSS version 29 and R 3.5.1 software.

RESULTS

In 2022, 86.5% (83/96) of nasopharyngeal samples were positive for at least one pathogen. Human rhinovirus/human enterovirus was the most frequent agent, followed by human respiratory syncytial virus, adenovirus and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Co-infections were observed in 43.3% of positive cases. Infection rates were significantly higher in children under 1 year of age, particularly for SARS-CoV-2 and human respiratory syncytial virus. Seasonal variations were observed, with human respiratory syncytial virus predominating in November, SARS-CoV-2 in January and human parainfluenza virus-4 in May. Molecular analysis of human respiratory syncytial virus revealed a shift in subtype prevalence, with both human respiratory syncytial virus-A and -B co-circulating in the pre-pandemic period, whereas only human respiratory syncytial virus-B was detected in the post-pandemic period.

CONCLUSION

Our data indicate changes in the distribution of respiratory viruses in the post-pandemic period compared to pre-pandemic period. The high prevalence of co-infections highlights the complexity of acute respiratory infection aetiology, emphasising the need for enhanced respiratory virus surveillance systems in Cabo Verde. Identifying seasonal trends and risk factors can contribute to targeted interventions and improved public health strategies to mitigate the burden of acute respiratory infections in young children.

The global burden of Klebsiella pneumoniae-associated lower respiratory infection in 204 countries and territories, 1990-2021: Findings from the global burden of disease study 2021

This study investigates the global epidemiological burden of lower respiratory infections (LRI) attributable to Klebsiella pneumoniae from 1990-2021, using data from the Global Burden of Disease Study (GBD) 2021. The findings reveal that globally, disability-adjusted life years (DALYs) from Klebsiella pneumoniae-associated LRI decreased from 16,701,044 (95% UI: 14,220,055-19,183,469) in 1990-6,935,440 (95% UI: 5,953,328-8,007,786) in 2021, while deaths declined from 239,367 (95% UI: 212,553-268,072) -175,783 (95% UI: 158,749-193,924). The age-standardized DALYs rate dropped from 313.1 (95% UI: 266.6-359.7)-87.9 (95% UI: 75.4-101.5), and the death rate decreased from 4.5 (95% UI: 4.0-5.0)-2.2 (95% UI: 2.0-2.5). In 2021, the highest rates were observed in Oceania and Sub-Saharan Africa, particularly in Central African Republic, Niger, and Zimbabwe, while the lowest rates were found in Australasia, High-income North America, Eastern Europe, and East Asia, especially in the UAE, Australia, and Qatar. Higher rates were noted among both males and females under 10 and over 65 years old. Although most regions experienced decreases in age-standardized rates(ASR) from 1990-2021, Southern Latin America exhibited an increase. Additionally, age-standardized DALYs and death rates generally declined with increasing socio-demographic index (SDI). The global burden of LRI due to Klebsiella pneumoniae significantly decreased over the study period, but lower SDI regions, children, and the elderly remain vulnerable and require targeted interventions to further reduce this burden.

Establishing normative physiological values among breastfeeding infants in Malawi for the development of a pneumonia dysphagia risk score

BACKGROUND

Pneumonia is the leading infectious cause of death in children under 5 years of age in low- and middle-income countries (LMICs), with most deaths among infants. In children with pneumonia, aspiration events have been implicated in fatalities; however, physiological data on normative infant feeding patterns and validated techniques for detecting dysphagia and aspiration risk in LMICs are lacking. We aimed to establish a baseline of normative physiological and behavioural feeding-related variables in healthy, well, breastfeeding infants in Malawi to begin developing dysphagia risk scoring tools for infants with severe pneumonia.

METHODS

We enrolled healthy breastfeeding infants (<12 months) without known dysphagia risk factors who presented to a vaccination clinic in Lilongwe, Malawi. We incorporated key variables from the literature and expert opinion to create a feeding evaluation protocol. We collected sociodemographic and clinical information and evaluated infants during 5 minutes of breastfeeding. Descriptive statistics and distributions of feeding variables were used to develop two dysphagia risk scoring tools for predicting wet breath sounds during feeding, a proxy for increased aspiration risk. We assessed initial tool performance by calculating test statistics.

RESULTS

We enrolled 100 infants and analysed data from 95 healthy, well participants. The median age was 4 months (IQR 1-6) and 60% (57/95) were female. During feeding, 55% (52/95) had more than one wet breath sound and 17% (16/95) had more than one cough. The two scoring tools classified 2.1% (2/95) and 3.2% (3/95) of participants as 'at risk' for dysphagia. The specificity of each scoring tool was 100% in detecting wet breath sounds during feeding.

CONCLUSION

We demonstrated that healthy, well Malawian infants exhibit variable vital signs and feeding behaviours during breastfeeding, and these data can be used to develop dysphagia risk scoring tools. Our next steps include evaluating and refining the tools to predict wet breath sounds in infants with severe pneumonia.

The role of TLR4/NF-kB signaling axis in pneumonia: from molecular mechanisms to regulation by phytochemicals

Pneumonia, a leading global health challenge, is characterized by inflammation driven by dysregulated immune responses. Central to its pathogenesis is the Toll-like receptor 4 (TLR4)/nuclear factor-κB (NF-κB) signaling axis, which orchestrates the recognition of pathogen-associated molecular patterns (PAMPs) and initiates cascades that mediate innate immunity. While this pathway is essential for bacterial clearance, its overactivation can lead to excessive inflammation, tissue damage, and severe complications, including acute respiratory distress syndrome (ARDS) and sepsis. This review examines the role of the TLR4/NF-κB axis in pneumonia caused by various pathogens, including Streptococcus pneumoniae, Staphylococcus aureus, and SARS-CoV- 2, and highlights its dual role in immune defense and pathological inflammation. Furthermore, we explore molecular regulators and phytochemicals that modulate this axis, including baicalin, resveratrol, and sodium houttuyfonate, which exhibit promising therapeutic potential. By elucidating these mechanisms, this study provides insights into targeted interventions to balance immune responses and mitigate inflammation, paving the way for innovative treatments in pneumonia management.

Investigating the acute effects of black carbon, PM2.5 exposure, and temperature on asthma and respiratory-related emergency department visits and hospitalizations in Mississippi

Globally, exposure to air pollutants (black carbon (BC) and fine particulate matter (PM2.5)) is associated with respiratory diseases, however, research is limited in the Southern United States, particularly in Mississippi. This study investigated the influence of BC, PM2.5, and temperature on daily asthma and respiratory emergency department visits and hospital admissions among individuals ≥65 years old in the Jackson, Mississippi Metropolitan Statistical Area (MSA), over a two-year period. Time-series analysis explored the exposure-lag-response relationship between environmental factors and asthma and respiratory outcomes. During the study period, a total of 1466 asthma-related and 9482 respiratory disorder-related admissions were recorded with females representing 74 % of asthma-related and 59 % of respiratory disorder-related admissions. An interquartile range (IQR: 1.42 μg m-3) increase in BC concentration was associated with an increased risk of respiratory disorder-related admissions at lag 0, with a RR of 1.013 (95 % CI: 1.001-1.026) for all data, and an RR of 1.020 (95 % CI: 1.003-1.038) for the female subgroup. Neither BC nor PM2.5 was identified to be associated with asthma-related admissions. Springtime exposure to an IQR increase in BC (1.42 μg m-3) and PM2.5 (6.91 μg m-3) significantly increased the risk of asthma-related admissions at lag 1, with a RR of 1.490 (95 % CI: 1.207-1.840) and 1.471 (95 % CI: 1.010-2.143), respectively. Lower temperatures increased the risk of respiratory disorder-related admissions, with elevated RRs observed 10-25 days post-exposure. This study indicates that BC exposure, particularly among females, was more strongly associated with respiratory disorder-related admissions than PM2.5 exposure. Temperature variations exhibited a significant impact on respiratory disorder-related admissions compared to asthma-related admissions. BC revealed a significant antagonistic interaction with temperature, while PM2.5 showed no interaction. Identifying environmental factors affecting human health in disparity-prone areas like Mississippi is crucial to protect public health.

Trypstatin as a Novel TMPRSS2 Inhibitor with Broad-Spectrum Efficacy against Corona and Influenza Viruses

Respiratory viruses, such as SARS-CoV-2 and influenza, exploit host proteases like TMPRSS2 for entry, making TMPRSS2 a prime antiviral target. Here, the identification and characterization of Trypstatin, a 61-amino acid Kunitz-type protease inhibitor derived from human hemofiltrate are reported. Trypstatin inhibits TMPRSS2 and related proteases with high potency, exhibiting half-maximal inhibitory concentration values in the nanomolar range, comparable to the small molecule inhibitor camostat mesylate. In vitro assays demonstrate that Trypstatin effectively blocks spike-driven entry of SARS-CoV-2, SARS-CoV-1, MERS-CoV, and hCoV-NL63, as well as hemagglutinin-mediated entry of influenza A and B viruses. In primary human airway epithelial cultures, Trypstatin significantly reduces SARS-CoV-2 replication and retained activity in the presence of airway mucus. In vivo, intranasal administration of Trypstatin to SARS-CoV-2-infected Syrian hamsters reduces viral titers and alleviates clinical symptoms. These findings highlight Trypstatin's potential as a broad-spectrum antiviral agent against TMPRSS2-dependent respiratory viruses.

Nomogram for prediction of plastic bronchitis in Chinese children with pneumonia

Background

This study investigated risk factors for plastic bronchitis (PB) in children with pneumonia and created a nomogram for early detection.

Methods

We retrospectively analyzed data from 487 children with pneumonia who underwent bronchoscopic alveolar lavage between 2018 and 2024. Children were divided into a PB group (n = 65) and a No-PB group (n = 422). Key indicators were identified using regression analysis, and a nomogram prediction model was developed. Its effectiveness was evaluated using receiver operating characteristic (ROC) curves, calibration curves, decision curve analysis (DCA), and the bootstrap (BS) method.

Results

A total of 65 patients (13.3%) out of 487 had PB. Multivariate logistic regression analysis indicated that mycoplasma infection, atelectasis, high fever peak, high neutrophil levels and elevated lactate dehydrogenase levels were risk factors for PB development. Additionally, the BS-ROC curve of the developed nomogram had an area under the curve value of 0.857 (95% confidence interval: 0.808-0.905). The calibration curve analysis revealed a strong agreement between the actual and predicted probabilities of PB development, and DCA highlighted the clinical relevance of the nomogram.

Conclusions

A nomogram for MP infection, fever peak, LDH, maximum neutrophils percentage (N%max), and atelectasis was established to predict the risk of PB in children with pneumonia. The nomogram effectively identifies PB early, and bronchoscopy is advised for high-risk children. However, the nomogram needs external validation before practical use.

Association between hospitalised childhood pneumonia and follow-up chest radiographs in high-risk populations: a secondary analysis of a multicentre randomised controlled trial

OBJECTIVE

As children hospitalised with community-acquired pneumonia (CAP) are at risk of persistent chest radiograph (CXR) abnormalities and respiratory sequelae, we investigated factors associated with incomplete CXR resolution at 4 weeks and 12 months post-discharge in children from populations at high-risk of chronic lung disease.

DESIGN

Secondary analysis-multicentre, placebo-controlled, randomised controlled trial.

SETTINGS AND PATIENTS

324 children aged 3 months to ≤5 years hospitalised with radiographic-confirmed CAP were enrolled from seven hospitals in Australia, New Zealand and Malaysia. After 1-3 days of intravenous antibiotics, then 3 days of oral amoxicillin-clavulanate, they were randomised to extended (13-14 days) or standard (5-6 days) courses of antibiotics.

INTERVENTION

CXRs were performed at admission, 4 weeks, and 12 months post-discharge and reviewed in a blinded manner.

MAIN OUTCOME MEASURES

Radiographic changes of pneumonia at 4 weeks and 12 months post-discharge compared with admission CXRs.

RESULTS

Among children with interpretable CXRs, incomplete resolution was seen in 42/253 (17%) at 4 weeks, and 29/212 (14%) at 12 months. Characteristics at admission associated with incomplete CXR resolution at 4 weeks were previous pneumonia hospitalisation (adjusted odds ratio [ORadj])=6.46, 95% confidence interval [CI] 2.21 to 18.85) and increasing age (ORadj=0.60 per-year, 95% CI 0.38 to 0.94). Continuing respiratory symptoms/signs at 4 weeks post-discharge was also associated with incomplete resolution (OR=5.63, 95% CI 2.38 to 13.32). At 12 months, previous pneumonia hospitalisation was associated with persistent incomplete CXR resolution (OR=4.03, 95 % CI 1.25 to 13.02).

CONCLUSION

In high-risk settings, younger age, those with previous pneumonia hospitalisation, or ongoing respiratory symptoms/signs 4 weeks post-discharge from hospitalised CAP may be associated with incomplete CXR resolution. Consequently, follow-up imaging and monitoring may be warranted in these children.

Respiratory syncytial virus pulmonary infections in adults - disease burden and prevention

PURPOSE OF REVIEW

We highlight the evolving understanding of the burden of respiratory syncytial virus (RSV) in older adults and recent data on the three new vaccines.

RECENT FINDINGS

As well as a greater recognition of the amount of RSV infection in adults, and especially over 60 years of age, there has been a significant amount of study detailing the postacute burden including excess cardiovascular disease and loss of physical and cognitive functioning. Three new RSV vaccines now have published data for two seasons, and while direct comparison is not possible due to differences in the timing, methodology and populations studies, all show good efficacy with no serious side effects of concern.

SUMMARY

RSV causes a substantial amount of morbidity and mortality in older adults with both acute and longer term impacts. With effective vaccines now available clinicians should be advocating with their patients to prevent RSV infection.

Antibiotics for Paediatric Community-Acquired Pneumonia: What is the Optimal Course Duration?

Despite significant global reductions in cases of pneumonia during the last 3 decades, pneumonia remains the leading cause of post-neonatal mortality in children aged <5 years. Beyond the immediate disease burden it imposes, pneumonia contributes to long-term morbidity, including lung function deficits and bronchiectasis. Viruses are the most common cause of childhood pneumonia, but bacteria also play a crucial role. However, the optimal duration of antibiotic therapy for bacterial pneumonia remains uncertain in both low- and middle-income countries and in high-income countries. Knowing the optimal duration of antibiotic therapy for pneumonia is crucial for effective antimicrobial stewardship. This is especially important as concerns mount over rising antibiotic resistance in respiratory bacterial pathogens, which increases the risk of treatment failure. Numerous studies have focused on the duration of oral antibiotics and short-term outcomes, such as clinical cure and mortality. In contrast, only one study has examined both intravenous and oral antibiotics and their impact on long-term respiratory outcomes following pneumonia hospitalisation. However, study findings may be influenced by their inclusion criteria when children unlikely to have bacterial pneumonia are included. Efforts to differentiate between bacterial and non-bacterial pneumonia continue, but a validated, accurate, and simple point-of-care diagnostic test remains elusive. Without certainty that a child has bacterial pneumonia, determining the optimal duration of antibiotic treatment is challenging. This review examines the evidence for the recommended duration of antibiotics for treating uncomplicated pneumonia in otherwise healthy children and concludes that the question of duration is unresolved.

Severe Pneumonia

Severe pneumonia is a leading cause of mortality and morbidity worldwide. Being a complex condition caused by a variety of microorganisms including bacteria, viruses, and fungi, it requires intensive care. A combination of early initiation of antimicrobial therapy and adjunctive nonantimicrobial interventions improve patient outcomes. This article reviews the most recent data on the epidemiology, microbiology, diagnosis, and management of severe pneumonia.

Bacterial genome structural variation: prevalence, mechanisms, and consequences

A vast number of bacterial genome sequences are publicly available. However, the majority were generated using short-read sequencing, producing fragmented assemblies. Long-read sequencing can generate closed assemblies, and they reveal that bacterial genome structure, the order and orientation of genes on the chromosome, is highly variable for many species. Growing evidence suggests that genome structure is a determinant of genome-wide gene expression levels and thus phenotype. We review this developing picture of genome structure variation among bacteria, the challenges for the study of this phenomenon, and its impact on adaptation and evolution, including virulence and infection.

Pathogenic profiles and lower respiratory tract microbiota in severe pneumonia patients using metagenomic next-generation sequencing

INTRODUCTION

The homeostatic balance of the lung microbiota is important for the maintenance of normal physiological function of the lung, but its role in pathological processes such as severe pneumonia is poorly understood.

METHODS

We screened 34 patients with community-acquired pneumonia (CAP) and 12 patients with hospital-acquired pneumonia (HAP), all of whom were admitted to the respiratory intensive care unit. Clinical samples, including bronchoalveolar lavage fluid (BALF), sputum, peripheral blood, and tissue specimens, were collected along with traditional microbiological test results, routine clinical test data, and clinical treatment information. The pathogenic spectrum of lower respiratory tract pathogens in critically ill respiratory patients was characterized through metagenomic next-generation sequencing (mNGS). Additionally, we analyzed the composition of the commensal microbiota and its correlation with clinical characteristics.

RESULTS

The sensitivity of the mNGS test for pathogens was 92.2% and the specificity 71.4% compared with the clinical diagnosis of the patients. Using mNGS, we detected more fungi and viruses in the lower respiratory tract of CAP-onset severe pneumonia patients, whereas bacterial species were predominant in HAP-onset patients. On the other hand, using mNGS data, commensal microorganisms such as Fusobacterium yohimbe were observed in the lower respiratory tract of patients with HAP rather than those with CAP, and most of these commensal microorganisms were associated with hospitalization or the staying time in ICU, and were significantly and positively correlated with the total length of stay.

CONCLUSION

mNGS can be used to effectively identify pathogenic pathogens or lower respiratory microbiome associated with pulmonary infectious diseases, playing a crucial role in the early and accurate diagnosis of these conditions. Based on the findings of this study, it is possible that a novel set of biomarkers and predictive models could be developed in the future to efficiently identify the cause and prognosis of patients with severe pneumonia.

Mortality among children aged 28 days-17 years with pneumonia who are not severely undernourished and the effect of macronutrient supplementation: a systematic review and meta-analysis

OBJECTIVE

Pneumonia is associated with four times higher odds of death among children with severe undernutrition. However, there is an equipoise for the mortality of children without severe undernutrition and the impact of macronutrient interventions. We collated evidence on mortality, anthropometric outcomes and the effect of macronutrient interventions in the management of non-severely undernourished children (28 days-17 years) with pneumonia globally.

DESIGN

Systematic review and meta-analysis using a priori criteria developed following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guideline.

DATA SOURCES

PubMed, Medline, EMBASE, Web of Science, Google Scholar, Scopus, Cochrane Central and bibliographies were searched between January 2000 and July 2024.

ELIGIBILITY CRITERIA

We included articles conducted among children between 28 days and 17 years with pneumonia and non-severe malnutrition that reported on mortality and changes in anthropometric status or macronutrient supplementation. Studies conducted exclusively among adults, on micronutrient supplementation, case studies, commentaries and reviews were excluded.

DATA EXTRACTION AND SYNTHESIS

Two reviewers independently screened, abstracted the data and conducted risk of bias (RoB) using standard criteria including the RoB in non-randomised follow-up studies of exposure for observational studies and the revised Cochrane RoB assessment tool for randomised studies (RoB 2.0). Heterogeneity was assessed using the I2 statistic, and subgroup analysis was done. Data were analysed using both narrative and quantitative synthesis. Quantitative synthesis was done using the maximum likelihood random-effects model in STATA V.18.0, with the 'meta_es' command.

RESULTS

A total of 15 articles were included (11 conducted in sub-Saharan Africa and four in Asia), with 169 901 participants overall. The mortality among non-severely undernourished children with pneumonia was 3.0% (95% CI 2% to 5%, I2=99.38%), with a range of 1-13% across studies. Children with moderate undernutrition had a higher overall mortality, 9.0% (95% CI 6% to 13%, I2=89.50%), than well-nourished children, with a range of 3-19% across studies. Only one of the 15 studies reported anthropometric outcomes during follow-up and compared mortality rates of those who did versus did not receive macronutrients. The study results were inconclusive.

CONCLUSIONS

Mortality among non-severely undernourished children with pneumonia ranges between 1-13% globally. There is inadequate follow-up nutritional assessment and management for non-severely undernourished children with pneumonia.

PROSPERO REGISTRATION NUMBER

CRD42021257272.

Time series analysis of the impact of air pollutants on influenza-like illness in Changchun, China

BACKGROUND

Emerging evidence links air pollution to respiratory infections, yet systematic assessments in cold regions remain limited. This study evaluates the short-term effects of six major air pollutants on influenza-like illness (ILI) incidence in Changchun, Northeast China, with implications for air quality management and respiratory disease prevention.

METHODS

ILI surveillance data from Changchun were extracted from "China Influenza Surveillance Network" and the ambient air quality monitoring data of the city were collected from 2017 to 2022. A generalized additive model (GAM) with quasi-Poisson regression analysis was employed to quantify pollutant-ILI associations, adjusting for meteorological factors and temporal trends.

RESULTS

Among 84,010 ILI cases, immediate exposure effects were observed: each 10 µg/m³ increase in PM2.5 (ER = 1.00%, 95% CI: 0.63-1.37%), PM10 (0.90%, 0.57-1.24%), and O3 (1.05%, 0.44-1.67%) significantly elevated ILI risks. Young and middle-aged individuals (25-59 years old) exhibited the highest susceptibility to five pollutants (PM2.5, PM10, SO2, O3, and CO), and age subgroups under 15 years old exhibited susceptibility to NO2. Post-COVID-19 outbreak showed amplified effects across all pollutants (p < 0.05 vs. pre-outbreak). The effects of PM2.5, PM10, SO2 and O3 on ILI cases were greater in the cold season (October to March) (p < 0.05).

CONCLUSIONS

PM2.5, PM10, and O3 exposure significantly increases ILI risks in Changchun, particularly among young/middle-aged populations during cold seasons and post-pandemic periods. These findings underscore the urgency for real-time air quality alerts and targeted protection strategies during high-risk periods to mitigate respiratory health burdens.

Bacterial pneumonia induces senescence in resident alveolar macrophages that are outcompeted by monocytes

Alveolar macrophages (AMs) are lung-resident macrophages critical to lung homeostasis and immunity. Replacement of embryonic-derived tissue-resident AMs (TRAMs) by circulating monocyte-derived AMs (MoAMs) reshapes the functionality of AMs and host susceptibility to respiratory diseases. However, mechanisms underlying such an AM turnover remain unclear. Using a mouse model of Streptococcus pneumoniae (S.P.) infection, we show here that respiratory S.P. infection induces the recruitment and differentiation of MoAMs, which dominate the post-infectious AM population and are functionally hyperresponsive. This turnover of AMs is not due to S.P.-induced irreversible loss of TRAMs. Instead, TRAMs experience a quick recovery in cell number shortly after the resolution of S.P. infection. While S.P.-experienced TRAMs keep the potential of long-term self-maintenance in a non-competitive environment, they demonstrate cellular senescence and a reduced rate of homeostatic proliferation and are, therefore, outcompeted by MoAMs. These data provide new insights into the mechanisms and functional significance of AM turnover during pulmonary bacterial infection.

Epidemiological trends and risk factors of chronic obstructive pulmonary disease in young individuals based on the 2021 global burden of disease data (1990-2021)

OBJECTIVE

Recent studies have shown that chronic obstructive pulmonary disease (COPD) in young individuals cannot be ignored. This study aims to investigate the burden of COPD and its associated risk factors in individuals aged 15 to 49 years, with a particular focus on health inequities across different levels of socioeconomic development.

METHODS

By analyzing data from the Global Burden of Disease (GBD) 2021, we utilized statistical methods such as Joinpoint regression, frontier analysis, and health inequality analysis to evaluate the changes in the age-standardized disability-adjusted life year (DALY) rates (ASDR) and incidence rates (ASIR) of COPD among the global population aged 15-49 years from 1990 to 2021. We specifically examined the disparities in health across countries and regions with varying levels of socioeconomic development. Key risk factors, including particulate matter pollution, smoking, and occupational exposure, were analyzed.

RESULTS

The number of COPD cases among young people globally has significantly increased.While the global ASDR and ASIR of COPD in the 15-49 age group showed an overall declining trend, the burden of COPD remained high in low Sociodemographic Index (SDI) regions and there were significant health inequalities between countries. Particulate matter pollution (41.79%), smoking (19.81%), and occupational exposure (11.73%) were identified as the primary contributors to the burden of COPD in younger individuals. In low SDI regions, particulate matter pollution had a particularly significant impact, accounting for 58.65% of attributable proportion of DALYs, and remained at a persistently high level. Smoking continued to contribute significantly to the burden of COPD in high-income regions, notably in North America, where smoking accounted for 34.26% of DALYs in 2021.

CONCLUSION

Although there is a global downward trend in the burden of COPD among young people, significant health inequities persist in low SDI regions. The findings emphasize the need for more effective public health activities targeting younger populations and low SDI countries and regions, particularly in improving air quality, reducing smoking, and mitigating occupational exposures.

CLINICAL TRIAL NUMBER

Not applicable.

Viral metagenomics reveals diverse viruses in the fecal samples of children with acute respiratory infection

Introduction

Changes in the gut microbiome have been associated with the development of acute respiratory infection (ARI). However, due to methodological limitations, our knowledge of the gut virome in patients with ARIs remains limited.

Methods

In this study, fecal samples from children with ARI were investigated using viral metagenomics.

Results

The fecal virome was analyzed, and several suspected disease-causing viruses were identified. The five viral families with the highest abundance of sequence reads were Podoviridae, Virgaviridae, Siphoviridae, Microviridae, and Myoviridae. Additionally, human adenovirus, human bocavirus, human astrovirus, norovirus, and human rhinovirus were detected. The genome sequences of these viruses were respectively described, and phylogenetic trees were constructed using the gene sequences of the viruses.

Discussion

We characterized the composition of gut virome in children with acute respiratory infections. However, further research is required to elucidate the relationship between acute respiratory infection and gut viruses.

Treatment with Ceftazidime-Avibactam for Lower Respiratory Tract Infections Caused by the Multidrug-Resistant Gram-Negative Bacteria in the Intensive Care Unit

Purpose

Ceftazidime avibactam (CAZ-AVI) is recommended for treating severe infections caused by multidrug-resistant gram-negative bacteria (MDR-GNB). However, there are few real-world studies on the use of CAZ-AVI to treat lower respiratory tract infections (LRTIs) caused by MDR-GNBs in intensive care units (ICUs). This study aimed to evaluate the clinical characteristics of patients with LRTIs caused by MDR-GNB who were treated with CAZ-AVI in the ICU, and to investigate the independent risk factors for mortality.

Patients and Methods

This single-center retrospective study included patients with LRTIs treated with CAZ-AVI in the respiratory ICU of a tertiary hospital in Anhui Province between December 2022 and November 2024. The primary outcomes were 28-day survival and independent risk factors for all-cause mortality.

Results

A total of 71 patients were enrolled in the study and 56.3% (40/71) had 28-day survival outcomes. The Acute Physiology and Chronic Health Evaluation (APACHE) II score (odds ratio [OR]: 1.144, 95% confidence interval [CI]: 1.012-1.293, p=0.032), coinfection with Aspergillus (OR: 42.753, 95% CI: 2.324-786.555, p=0.011), and days of CAZ-AVI (OR: 0.851, 95% CI: 0.734-0.986, p=0.032) were independent risk factors for 28-day all-cause mortality. Kaplan-Meier analysis demonstrated prolonged CAZ-AVI therapy (>10 days) improved survival (p<0.001), APACHE II scores >24 correlated with increased 28-day mortality (p=0.0048), and Aspergillus coinfection significantly reduced survival rates (p=0.001). We also constructed a nomogram for predicting the risk of death in ICU patients treated with CAZ-AVI for LRTIs, with good discrimination and calibration.

Conclusion

CAZ-AVI can be used to treat LRTIs caused by MDR-GNB in the ICU. Higher APACHE II scores and coinfection with Aspergillus were associated with 28-day mortality, whereas a longer course of therapy was a protective factor. The nomogram can help clinicians predict CAZ-AVI outcomes.

Structure, Function, and Regulation of LytA: The N-Acetylmuramoyl-l-alanine Amidase Driving the "Suicidal Tendencies" of Streptococcus pneumoniae-A Review

Streptococcus pneumoniae (pneumococcus) is a significant human pathogen responsible for a range of diseases from mild infections to invasive pneumococcal diseases, particularly affecting children, the elderly, and immunocompromised individuals. Despite pneumococcal conjugate vaccines having reduced disease incidence, challenges persist due to serotype diversity, vaccine coverage gaps, and antibiotic resistance. This review highlights the role of LytA, a key autolysin (N-acetylmuramoyl-l-alanine amidase), in pneumococcal biology. LytA regulates autolysis, contributes to inflammation, and biofilm formation, and impairs bacterial clearance. It also modulates complement activation, aiding immune evasion. LytA expression is influenced by environmental signals and genetic regulation and is tied to competence for genetic transformation, which is an important virulence trait, particularly in meningitis. With the increase in antibiotic resistance, LytA has emerged as a potential therapeutic target. Current research explores its use in bacteriolytic therapies, vaccine development, and synergistic antibiotic strategies. Various compounds, including synthetic peptides, plant extracts, and small molecules, have been investigated for their ability to trigger LytA-mediated bacterial lysis. Future directions include the development of novel anti-pneumococcal interventions leveraging LytA's properties while overcoming vaccine efficacy and resistance-related challenges. Human challenge models and animal studies continue to deepen our understanding of pneumococcal pathogenesis and potential treatment strategies.

Burden of non-COVID-19 lower respiratory infections in China (1990-2021): a global burden of disease study analysis

BACKGROUND

The assessment of lower respiratory infection (LRI) mortality, incidence, and responsible pathogens in China provides a scientific basis for the prevention and management of LRI, especially for evaluating the impact of coronavirus disease 2019 (COVID-19). We provide a national estimate of the non-COVID-19 LRI burden and trends on people from 1990 to 2021 based on Global Burden of Disease (GBD) study 2021.

METHODS

We estimated China's mortality, incidence, disability-adjusted life years (DALYs), risk factors and aetiology attribution for LRI without including COVID-19 by using the estimated data of GBD study 2021. Mortality, incidence, DALYs, risk factors and aetiology were stratified by sex and age. Trends were evaluated using estimated annual percentage change.

RESULTS

In 2021, it is estimated that there were 206930.22 deaths (95% uncertainty interval [UI]: 171260.88-251990.47), with all-age mortality rate of 14.54 deaths (95% UI: 12.04-17.71) per 100,000 population. Compared to 2019, the all-age mortality rate had a 3.60% increase. Analyzing risk factors from 1990 to 2021, we found that the percentage of DALYs attributed to tobacco increased from 7.44% (95% UI: 1.26-15.72%) to 22.14% (95% UI: 3.28-38.41%), and that attributable to ambient particulate matter pollution increased from 19.84% (95% UI: 8.79-30.20%) to 32.72% (95% UI: 22.78-41.77%). The leading cause of mortality from LRIs remains Streptococcus pneumoniae from 1990 to 2021. However, the proportions of viral infections decreased. Compared to 2019, the proportion of deaths in 2021 caused by Influenza decreased from 13.03 to 2.70%, and the proportion of deaths due to RSV decreased from 2.21 to 0.41%.

CONCLUSIONS

In China, substantial progress has been made in reducing LRI mortality, yet LRIs have remained a threat in China from 1990 to 2021. During the COVID-19 pandemic, the mortality attributable to Influenza and RSV declined. Effective vaccines and treatments targeted at the main pathogens of LRI are important.

CLINICAL TRIAL NUMBER

Not applicable.

The Integrated Pulmonary Immune Response to Pneumonia

Pneumonia is an acute respiratory infection of the lower respiratory tract. The effectiveness of the host immune response determines the severity of infection, or whether pneumonia occurs at all. The lungs house both innate and adaptive immune systems, which integrate their activities to provide host defense that eliminates microbes and prevents lower respiratory infection from becoming severe. Professional immune cells in the lung, like macrophages and lymphocytes, work with lung constituents, like epithelial cells and fibroblasts, to optimize antimicrobial defense. The dynamics of the immune response during infection and the immune components contributing to defense are influenced by prior experiences with respiratory pathogens, remodeling lung immunity in ways that improve responses against subsequent infections. This review covers how innate and adaptive immune activities coordinate inside the lung to provide integrated and effective immune resistance against respiratory pathogens.

Health inequalities in respiratory tract infections - beyond COVID-19

PURPOSE OF REVIEW

To discuss recent findings on the global burden of respiratory tract infections in underprivileged populations, highlighting the critical role of socioeconomic factors in the incidence and severity of these diseases, with a particular focus on health disparities affecting Indigenous communities.

RECENT FINDINGS

Pulmonary tuberculosis and lower respiratory tract infections, particularly those caused by Streptococcus pneumoniae and respiratory syncytial virus (RSV), continue to disproportionally impact populations in low-income countries and Indigenous communities worldwide. Indigenous children <5 years old bear the highest global burden of RSV infection, reflecting persistent social inequalities between Indigenous and non-Indigenous populations. Repeated episodes of acute pneumonia during childhood significantly contribute to the high prevalence of chronic respiratory diseases among Indigenous populations. The widespread occurrence of bronchiectasis in these communities is closely linked to adverse socioeconomic conditions.

SUMMARY

Significant disparities in the incidence and severity of lower respiratory tract infections between affluent and impoverished populations are driven by socioeconomic inequalities. Vaccinating vulnerable population groups with newly developed vaccines has the potential to prevent infections caused by pathogens such as S. pneumoniae and RSV. However, global access to these vaccines and monoclonal antibodies remains limited due to their high costs.

Development of a nasal spray based on cyclodextrin/hydrophobically-modified hydroxypropyl-methyl cellulose for the prevention of viral respiratory infections

The work aims to develop mucoadhesive and thermo-responsive in situ gelling systems, using hydrophobically-modified hydroxypropyl-methyl cellulose (Sangelose, SG) and beta-cyclodextrin (β-CD) derivatives, for preventing viral respiratory infections. Eight SG/CD systems with varying CD concentrations were evaluated for rheological properties, mucoadhesiveness, spreadability and sprayability via nasal devices; cytotoxicity was in vitro investigated on reconstituted nasal epithelia. Additionally, droplet size distribution and spray deposition were assessed for the most promising systems. The addition of β-CD derivatives to SG solution was responsible for a rapid sol-gel transition within a physiological temperature range (29-34 °C). SG/CD systems were characterized by a prevalence of the elastic properties on the viscous ones at 37 °C, functional to the formation of a protective gel barrier on the mucosa. The most promising systems showed sprayability and spreadability suitable for nasal administration, while in vitro tests demonstrated their non-toxicity. All the sprays were characterized by droplets with size >100 μm, functional to avoid droplet exhalation or lung deposition; spray deposition studies confirmed uniform distribution across nasal turbinates, crucial for trapping inhaled particles. In conclusion, a mucoadhesive and thermo-responsive in situ gelling system consisting of SG and β-CD derivatives was successfully developed as promising nasal spray for the prevention of respiratory infections.

Excess Respiratory Hospitalisations Associated with Influenza, Respiratory Syncytial Virus and SARS-CoV-2 in Singapore from 2015 to 2023

BACKGROUND

The patterns of circulation and burden of influenza and respiratory syncytial virus (RSV) in Singapore are affected by the COVID-19 pandemic containment measures. These patterns in relation to SARS-CoV-2 in a post-pandemic era are unclear.

METHODS

Using data from 2015 to 2023, we estimated excess influenza-, RSV- and SARS-CoV-2-associated hospitalisation in Singapore, adjusted for rhinovirus/enterovirus activity in generalised additive models. The data include pneumonia and influenza (P&I) hospitalisation from a national inpatient database and a community-wide acute respiratory infection (ARI) sentinel surveillance programme, stratified by age groups.

RESULTS

Across all age groups, the proportion of hospitalisation associated with influenza, SARS-CoV-2 and RSV was 13.2% (95% CI 5.0%-21.6%), 19.3% (95% CI 13.8%-25.0%) and 4.0% (95% CI 0.9%-12.1%) in 2023, respectively. From 2019 to 2023, all-age influenza-associated hospitalisation declined from 264.4 per 100,000 person-years (95% CI 214.2-313.2) to 203.7 per 100,000 person-years (95% CI 76.8-333.6). In contrast, all-age RSV-associated hospitalisation after the pandemic was 62.2 per 100,000 person-years (95% CI 13.8-186.9), similar to pre-pandemic observations. Peak seasonal influenza occurred 3-8 weeks later as compared with the time of pre-pandemic peak influenza activity.

CONCLUSION

The overall burden of influenza has declined after the COVID-19 pandemic and its burden is comparable with SARS-CoV-2. Furthermore, shifts in the timing of peak influenza activity suggest a potential need to review the timing of vaccine recommendations in Singapore.

The impact of the COVID-19 pandemic on antimicrobial usage: an international patient-level cohort study

Background

This study aimed to evaluate the trends in antimicrobial prescription during the first 1.5 years of COVID-19 pandemic.

Methods

This was an observational, retrospective cohort study using patient-level data from Bangladesh, Brazil, India, Italy, Malawi, Nigeria, South Korea, Switzerland and Turkey from patients with pneumonia and/or acute respiratory distress syndrome and/or sepsis, regardless of COVID-19 positivity, who were admitted to critical care units or COVID-19 specialized wards. The changes of antimicrobial prescription between pre-pandemic and pandemic were estimated using logistic or linear regression. Pandemic effects on month-wise antimicrobial usage were evaluated using interrupted time series analyses (ITSAs).

Results

Antimicrobials for which prescriptions significantly increased during the pandemic were as follows: meropenem in Bangladesh (95% CI: 1.94-4.07) with increased prescribed daily dose (PDD) (95% CI: 1.17-1.58) and Turkey (95% CI: 1.09-1.58), moxifloxacin in Bangladesh (95% CI: 4.11-11.87) with increased days of therapy (DOT) (95% CI: 1.14-2.56), piperacillin/tazobactam in Italy (95% CI: 1.07-1.48) with increased DOT (95% CI: 1.01-1.25) and PDD (95% CI: 1.05-1.21) and azithromycin in Bangladesh (95% CI: 3.36-21.77) and Brazil (95% CI: 2.33-8.42). ITSA showed a significant drop in azithromycin usage in India (95% CI: -8.38 to -3.49 g/100 patients) and South Korea (95% CI: -2.83 to -1.89 g/100 patients) after WHO guidelines v1 release and increased meropenem usage (95% CI: 93.40-126.48 g/100 patients) and moxifloxacin (95% CI: 5.40-13.98 g/100 patients) in Bangladesh and sulfamethoxazole/trimethoprim in India (95% CI: 0.92-9.32 g/100 patients) following the Delta variant emergence.

Conclusions

This study reinforces the importance of developing antimicrobial stewardship in the clinical settings during inter-pandemic periods.

Incidence of pneumococcal and all-cause pneumonia in adults in Catalonia following the implementation of universal pneumococcal vaccination in children: 2015-2016 vs. 2017-2018

INTRODUCTION

To analyze the incidence of pneumonia in adults following public funding of the 13-valent pneumococcal conjugate vaccine (PCV13) for children in Catalonia.

METHODS

Two cohorts were analyzed: 2,025,730 individuals aged ≥50 years in 2015-2016 (pre-funding) and 2,059,645 in 2017-2018 (post-funding). Hospitalizations for pneumococcal pneumonia (PP) and all-cause pneumonia (ACP) were identified through the CMBD database across 68 Catalonian hospitals. Incidence rate ratios (IRR) between periods were estimated.

RESULTS

PP incidence increased from 83.6/100,000 (2015-2016) to 90.7/100,000 (2017-2018) (IRR: 1.09; 95%CI: 1.03-1.14), while ACP decreased slightly from 617.9/100,000 to 609.7/100,000 (IRR: 0.99; 95%CI: 0.97-1.00). ACP reductions were significant in individuals aged 65-79, those with chronic lung disease, and men. PP increased significantly in those aged>80 years.

CONCLUSION

Adult hospitalized pneumonia incidence did not significantly decrease in the two years following PCV13 public funding for children.

Anesthetic choice impacts mortality and bacterial clearance in a murine experimental pneumonia model

BACKGROUND

Animal models of infectious pneumonia often require the use of anesthetics, but their choice and impact on outcome is rarely discussed. This study investigates the impact of the most commonly used anesthetics on mortality and bacterial clearance in a murine model of Pseudomonas aeruginosa pneumonia.

METHODS

Isoflurane or ketamine/xylazine were determined to be the most commonly utilized anesthetics for murine pneumonia models. Mice were anesthetized with either ketamine/xylazine or isoflurane during intratracheal infection with P. aeruginosa strains PA14 or PA01. Mortality, bacterial clearance, and lung tissue damage were compared. Additional in vitro assays assessed the effects of ketamine on human whole blood killing, serum killing, and neutrophil functions (reactive oxygen species (ROS) production, neutrophil extracellular trap (NET) production, chemotaxis, and phagocytosis).

RESULTS

Mice anesthetized with ketamine/xylazine and infected with PA14 had significantly increased mortality (p = 0.004), and significantly higher bacterial burdens in the blood (p = 0.01) and lungs (p < 0.001). In separate experiments with PA01, mice anesthetized with ketamine/xylazine had significantly increased mortality (p = 0.01), higher bacterial burdens in the blood (p = 0.01), and higher bacterial burdens in the lungs (p = 0.02), along with increased lung tissue pathology (p = 0.03) compared to mice anesthetized with isoflurane. Increased mortality and colony forming units were also observed in mice infected under propofol anesthesia, recovered, and subsequently exposed to ketamine versus control (p = 0.004 and p < 0.001, respectively). Ketamine marginally reduced the killing of PA14 in freshly drawn human whole blood (p = 0.0479), but had no significant effect on the serum's ability to kill PA14. In addition, ketamine reduced in vitro NETosis and chemotaxis (all p < 0.05), but had no significant effect on ROS production or phagocytosis of human neutrophils. These in vitro effects were observed only at supraclinical ketamine concentrations.

CONCLUSIONS

Our study emphasizes that the choice of anesthetic impacts key outcomes in murine models of pneumonia, and should therefore be an important consideration in experimental design and when comparing results across different studies.

The added value of diagnostics to characterize age-specific patterns of respiratory viral infections and coinfections and to detect emerging threats

BACKGROUND

Pandemic restrictions caused variation in respiratory virus circulation until the winter of 2022/23. The aim of this study was to monitor respiratory virus cases in the 2023/24 epidemic season.

METHODS

Children and adults attending Sapienza University Hospital for acute respiratory infections (October 2023-June 2024) were tested for respiratory viruses via molecular methods.

RESULTS

Of the 1121 patients included, 880 (78%) were positive for rhinovirus (HRV, 32%), Influenza A (IAV, 29%), and respiratory syncytial virus (RSV, 28%). RSV is more common in infants, and IAV is more common in adults, whereas HRV is more common in children aged 1-5 years. IAV, RSV and HRV cocirculate in winter; HRV cases also occur in spring, along with Influenza B (IBV) and other viruses. Despite circulating in the same weeks, the number of observed coinfections was much lower than that predicted for IAV and RSV (p <.0001) and lower also for the IAV/IBV, IBV/RSV and RSV/HRV pairs (p <.0001, p =.0059, p =.015, respectively). IAV and RSV cocirculated with different patterns in different age groups. In fact, in children aged 1-5 years, the RSV peak preceded that of IAV, whereas in older age groups, the RSV peak occurred toward the end of IAV circulation. Sequencing of HRV/EV cases in spring revealed 25 HRV genotypes and two EV-C105 cases.

CONCLUSIONS

Respiratory viruses can cause age-specific seasonal peaks that are modulated by viral interference phenomena. Molecular diagnostic data should be integrated with surveillance programs to characterize seasonal circulation patterns of common respiratory viruses and to rapidly detect the next pandemic threat.

Comparative Analysis of Metagenomic Next-Generation Sequencing, Sanger Sequencing, and Conventional Culture for Detecting Common Pathogens Causing Lower Respiratory Tract Infections in Clinical Samples

Metagenomic next-generation sequencing (mNGS) has emerged as a revolutionary tool for infectious disease diagnostics. The necessity of mNGS in real-world clinical practice for common Lower Respiratory Tract Infections (LRTI) needs further evaluation. A total of 184 bronchoalveolar lavage fluid (BALF) samples and 322 sputa associated with LRTI were fully examined. The detection performance was compared between mNGS and standard microbiology culture, using Sanger sequencing as the reference method. 52.05% (165/317) of sputa showed identical results for all three methods. Compared to Sanger sequencing, the same results obtained by mNGS were 88.20% (284/322). In 2.80% (9/322) of cases, Sanger sequencing detected more microorganisms, while mNGS detected more in 9% (29/322) of cases. For BALF, 49.41% (85/172) of cases showed identical results for all three methods. In 91.30% (168/184) of cases, identical results were produced by both mNGS and Sanger sequencing. mNGS detected more species in 7.61% (14/184) of cases, whereas in 2.80% (2/184) instances, the Sanger sequencing detected more microorganisms than mNGS. In the 184 BALF samples, 66 samples were identified as having co-infections by mNGS, Sanger sequencing identified 64 samples, and cultures identified 22 samples. Our study demonstrates that mNGS offers a significant advantage over conventional culture methods in detecting co-infections. For common bacterial pathogens, conventional culture methods are sufficient for detection. However, mNGS provides comprehensive pathogen detection and is particularly useful for identifying rare and difficult-to-culture pathogens.

Incidence and costs of hospitalisation due to acute respiratory infection in adults aged over 50 years in Jiangsu, China in 2019-23: a real-world medical database analysis of 0.2 million episodes

Background

Acute respiratory infection (ARI) poses a significant public health challenge worldwide, particularly among older adults. However, the disease and economic burden of ARI among older adults in China remained sparse. We aimed to estimate the incidence rate and medical cost of hospitalisation due to ARI among adults aged ≥50 years in Jiangsu Province, China.

Methods

We analysed medical records of hospitalised episodes due to ARI from January 2019 to May 2023 from a regionally representative medical database. We estimated hospitalisation rates and the proportion of severe cases (intensive care unit admission, mechanical ventilation, or death) by sex, age group, and time period. Total direct medical cost and out-of-pocket cost were estimated in CNY. We analysed factors influencing total costs using a multivariate linear regression model. We further compared the proportion of severe cases and medical cost between those with and without selected comorbidities.

Results

A total of 209 632 episodes of ARI hospitalisation were included. Over the study period, annualised ARI hospitalisation rate ranged from 1.07 to 1.83 per 1000 person-years, and varied by age, sex and region. Severe cases accounted for 6.5-10.3%. The median total direct medical cost was CNY 9027 (interquartile range (IQR) = 6118-14 886), of which 22% (IQR = 7-41) was out-of-pocket. Rural residents born a substantial out-of-pocket cost, which was even higher than their average monthly disposable income. Patients with certain comorbidities had higher medical costs despite having a similar or even lower proportion of severe cases.

Conclusions

By analysing a large regionally representative medical database, we helped address the knowledge gap in the burden and cost of ARI hospitalisation in China. While highlighting the overall substantial disease burden and cost of ARI, we identified important factors such as age, sex, region, and comorbidity that influence the disease burden and cost of ARI.

Autophagy and Respiratory Viruses: Mechanisms, Viral Exploitation, and Therapeutic Insights

Respiratory viruses, such as influenza virus, rhinovirus, coronavirus, and respiratory syncytial virus (RSV), continue to impose a heavy global health burden. Despite existing vaccination programs, these infections remain leading causes of morbidity and mortality, especially among vulnerable populations like children, older adults, and immunocompromised individuals. However, the current therapeutic options for respiratory viral infections are often limited to supportive care, underscoring the need for novel treatment strategies. Autophagy, particularly macroautophagy, has emerged as a fundamental cellular process in the host response to respiratory viral infections. This process not only supports cellular homeostasis by degrading damaged organelles and pathogens but also enables xenophagy, which selectively targets viral particles for degradation and enhances cellular defense. However, viruses have evolved mechanisms to manipulate the autophagy pathways, using them to evade immune detection and promote viral replication. This review examines the dual role of autophagy in viral manipulation and host defense, focusing on the complex interplay between respiratory viruses and autophagy-related pathways. By elucidating these mechanisms, we aim to highlight the therapeutic potential of targeting autophagy to enhance antiviral responses, offering promising directions for the development of effective treatments against respiratory viral infections.